1. Field of the Invention
This invention relates to an apparatus for overturning a roll, into which a long web has been wound up, from the state, in which the wind-up axis of the roll of the long web is approximately horizontal, to the state, in which the wind-up axis is approximately vertical.
2. Description of the Prior Art
As described in, for example, Japanese Unexamined Patent Publication No. 4(1992)-112172, long webs of photographic materials, and the like, are ordinarily wound up into rolls and dealt with in the form of the rolls. In many cases, the long web of this type is wound up in a wind-up apparatus into a roll such that the wind-up axis of the roll may be approximately horizontal. The tail end of the long web is then secured to the long-web roll. When the long-web roll is conveyed to the next process, in general, the long-web roll is conveyed by a conveyor in a stable orientation such that the wind-up axis of the long-web roll may be approximately vertical. Therefore, it is necessary to utilize an apparatus for overturning the long-web roll from the state, in which the wind-up axis of the long-web roll is approximately horizontal, to the state, in which the wind-up axis is approximately vertical.
As one of apparatuses for overturning a long-web roll, an apparatus shown in FIGS. 10A, 10B, 10C, and 10D has heretofore been known wherein two belt conveyors 51 and 52 are combined with each other such that they may be normal to each other. The belt conveyors 51 and 52 can be rotated by an angle of 90.degree. around a rotation shaft 53. With the illustrated conventional apparatus, a long-web roll 56 is placed on a belt conveyor 54 in an orientation such that a wind-up axis C of the long-web roll 56 may be approximately horizontal. As illustrated in FIG. 10A, the long-web roll 56, which has thus been conveyed by the belt conveyor 54, is received by the belt conveyor 51. As illustrated in FIG. 10B, the long-web roll 56 is conveyed by the belt conveyor 51 to the position that is in contact with the belt conveyor 52. Thereafter, as illustrated in FIG. 10C, the belt conveyors 51 and 52 are rotated around the rotation shaft 53, and the long-web roll 56 is thereby overturned to the orientation such that the wind-up axis C may be approximately vertical. As illustrated in FIG. 10D, the belt conveyor 52 is then driven in order to deliver the long-web roll 56 onto a belt conveyor 55.
With the conventional apparatus described above, the overturning operation cannot be begun immediately after the long-web roll 56 is received by the belt conveyor 51. The overturning operation can be begun only after the long-web roll 56 has been conveyed to the position shown in FIG. 10B. Also, after the overturning operation has been finished, the belt conveyors 51 and 52 cannot be immediately returned to the original positions. Specifically, as illustrated in FIG. 10D, only after the long-web roll 56 has been completely discharged from the belt conveyor 52 onto the belt conveyor 55, the belt conveyors 51 and 52 can be returned to the original positions. Therefore, the processing time per long-web roll cannot be kept short.
Further, the illustrated conventional apparatus is not provided with a means for holding the long-web roll 56 on the belt conveyors 51 and 52. Therefore, there is the risk that the position of the long-web roll 56 shifts due to inertia during the overturning operation, and the long-web roll 56 is thus scratched. Furthermore, there is the risk that the long-web roll 56 jumps up and down during the overturning operation. Accordingly, the problems occur in that the speed, with which the overturning operation is carried out, cannot be kept high.
As one of overturning apparatuses which are capable of quickly carrying out the overturning process, an apparatus has been proposed in, for example, Japanese Unexamined Utility Model Publication No. 56(1981)-72852, wherein articles are fed one after another onto a rotating impeller. The proposed conventional overturning apparatus is not provided with a means for holding the articles to be overturned. Therefore, there is the risk that the articles are scratched due to shift in position.
As one of overturning apparatuses provided with a mechanism for holding a roll, an apparatus has been proposed in, for example, Japanese Unexamined Patent Publication No. 5(1993)-58597, wherein a shaft provided with the holding mechanism is inserted into a core (i.e., a bobbin around which an electric wire has been wound up). With the proposed overturning apparatus, only the core is held. Therefore, in cases where the proposed overturning apparatus is applied to a long-web roll, the problems occur in that outer loops of the long web in the roll deviate in position along the axial direction of the long-web roll.